Intercooler



July 7, 1941 w. R. 'RA'MSAUR INTER-QCOLER Filed July 16, 1940 2Sheets-Sheet 1 INYENTOR.

ATTORNEY.

July 7, 1942. w. R. RAMSAUR 2,288,598

r INTER-COOLER I w Filed July 15, 1940 2 Sheets-Sheet 2 'llllllllIIIIII/I WA! 752 2 @Mf/IUE,

I N VEN TOR.

' ATTORNEY.

Patented July 1942 Walter R. ltamsaur, m Angeles, Calif.,

casino:-

to The Garrett Corporation, Airesearch Manufacturing Company. di acorporation of Califo vision, Los Angeles, Caliit.

- "Application July is, 1940,. Serial No. 345,756

My invention relates in general todevices wherein heat is transferredfrom one fluid to another, and relates in particular to an interposedinbanks and areflattened his direction lengthwise'of the-banks so thatportions of adiacent tubes are brought substantially into concooler forusewith superchargers such as em ployed with aircraft engines. i

In devices of this general character it is customary to provide apassage for the flow of a first fluid and to extend across this passagethin metal tubes through which a second fluid is passed in-heatexchanging relation to the flrst fluid. An object of the presentinvention is to provide a device of this character whereinincreasedefliciency of heat' transfer between the flrst and second fluidis accomplished by control .of the flow of these fluids.

It is an object of the present invention to tact so that thetubescooperate to form continuous walls which deflnepassages for the-flow of It is an object of the invention toprovide simple means forsecuring the streamlined fluid guide members inoperative relation thetubes 1 of an inter-cooler.

. I have found that expanding tubes through the full length thereof setsup strains on the end headers causing them. to warp, for the reasonprovide a device of the characterset forth'in the 1 foregoing havingstreamlined fluid guiding means at the mouthoi the fluid passages. Inthis device the fluid guiding means reduces turbulence in the fluidsentering the, passages so that the flow-retarding resistance in thefluid is mini mized and a greater velocity and quantity of fluid ispermitted to flow through the passages.-

It is an object of the invention to provide means for controlling theflow of both the coolantand of the fluid to be cooled so that greateremciency in, the .transfer of heat will be obtained. x

A further object of theinvention is 'to so form x and place the tubes ofaninter-cooler that paths of flow for a fluid will be established inwhich that when a tube is expanded diametrally it will generally shrinkin length. In my present in-' vention I expandthe tube at the pointsintermediate their lengthsvwhere-they pass through the intermediatesupporting baiiies or plates.

. Further objects andfiadvantages of the invention will be brought outin the following part of I the specification.

Referring to the drawings which are for illustrative purposes only:

Fig. 1 is a perspective view showing a preferred embodiment of myinter-cooler with fluid ducts connected thereto.

Fig. 2 is an enlarged fragmentary section of the corner of theintercooler included within the dotted encircling line 2 of Fig. 1.

Fig. 31s an enlarged fragmentary section taken I on a plane indicated bythe line 3-3 of Fig. 1.

there will be a minimumof flow retarding disturbance and wherein therewill be an increase cooling tube. cross-sectional area.

in the ratio of the cooling tube surface to the A further object of theinvention is to provide side-by-side relation, these tubes havingdiametrically opposed flat parallel walls and being soiplaced thatthe-flat walls are substantially aligned and define passages throughwhich a flow of fluid is conducted. A

A further object of the invention is to (provide an inter-cooler whereintubes of flattened cross-sectional area are extended across a fluidpassage. and it is a further'objectto provide a device of this characterwherein tubes of round cross-section are'secured in substantiallyparallel marginal walls of a fluid passage and are then flattenedbetween such marginalwalls and in a direction corresponding to the flowof fluid through the passage. 1

It'is a further object of the invention to provide an inter-coolerwherein the tubes are disan inter-cool'echaving a plurality "of tubes in45 7 intermediate plate-2Il, and four top and bottom wall members 21provided with flanges 22 wherex. by they may be secured to the upper andlower .rear flanges I3 and ii are substantiallyidentieai .dicatedbyfiarrows lid and lid. 4 second fluid through a plurality of tubes.which Fig. 4 is an enlarged fragmentary section taken as indicated bythe line 4-4 of Fig. 1.

- 'In Fig. 1 is shown an inter-cooler Ill having fittings) and I!connected to the front and rearflanges l3 and II thereof, .whereby afluid v may be passed through the inter-cooler II) as in- To conduct a;

extend across the inter-cooler from side-to-side" thereof I showfittings ii and it, through which the second fluid may I! and l8.

pass as indicated by arrows As best shown in Figs. 1 and 3, theinter-cooler. ill comprises a pair of vertical side plates ii, an

edges of the vertical plates l9 and 20 by means of bolts 23. Theside-plates l9 and the top and bottom walls 2| form a box which is'openat the front and rear ends thereof. The front and in form and'areconnected in the front and rear openings of the inter-cooler III bymeans of a. I

rectangular frame 24 having a portion to project within the edges oftheplates l9 and the upper and lower wall members 2|, as shown in Fig. 4,and being secured by means of bolts 25.

Horizontal banks 26, 21, etc., of tubes 28 are disposed within the shellof the inter-cooler to so as to pass from one side wall 19 to the other,

the central portions of these tubes 28 being supported by'theintermediate wall 20. Figs. 3 and 4, horizontal openings 29 are formedin the plates l9 and 20 in horizontal rows R, R2, R3, etc., thepositions of these rows of holes defining the horizontal planes in whichthe banks of tubes 28 will lie;

The ends of the tubes 28 are secured in the As shown in a 10 openings'29 of the side plates I9, preferably by expanding the ends of thesetubes in the openings, and, as shown in Figs. 2 and 3, supplementarysecuring means may be employed in the form of ferrules 30 which areexpanded within the end portions of the tubes 28 lying in the isexpanded into engagement with the wall of the opening 29, and theportions of the tube 28 ad-jacentthe ends of the opening 29 are expandedso as to produce shallow annular bulges 68, as shown in Fig. 3. Thebulges 68 form shoulders adjacent the, ends of the opening 29 tocooperate in limiting axial relative movement of the tubes and thewall28.

Thetubes 28 are flattened intermediate the ends thereof, so that theupper and lower portions 32of the metal wall of the tubes will extend inhorizontal planes, thereby providing spaced horizontal walls defininghorizontal air passages 33 between .the banks of tubes 28 through whicha fluid, such as air, may flow, as-

indicated by arrows 34. The spacing of the tubes 28 is such that whenthey are flattened, the

side portions 35 thereof will engage, as shown in Fig. 4, therebyforming of each bank of tubes a substantially continuous horizontalwall. The

effect of flattening the tubes 28 is to decrease the cross-sectionalarea of the space within each tube without decrease in the area of thetube wall, thereby increasing the ratioof the area of the tube surfaceto the volume of the interior space of the .tube in which a fluid ispassed in a heat exchanging relation to the fluid which moves throughthe horizontal spaces 33.]

At the front and rear edges of the banks of tubes 28 I place air guidingmeans 36 to reduce the agitation or turbulence of the air as it passesbetween the spaces 33 and the exterior. As best shown in Fig. 4 theseair guiding means comprise streamlined bars 36 seemed so as to lieadjacent the edges of the banks of tubes 28. The bars 36 each have arelatively narrow rounded front edge 31 with gradually expanding andslightly-curved upper'and lower walls 38 and 39.. The air entering themouth of the inter-cooler I 0, as indicated by arrows 48, is parted bythe forward edges 3l of the streamlined bars 36, and,- as indicatedbyarrows 4|, is caused to flow relatively smoothly over the upper andlower surfaces or walls'38 and 39 of the bars 36 into the passages 33between the banks of tubes 28.

edge portions of the plates l8 and 20 by means of brackets 42 and 43;The brackets 42' each have a supporting plate portion 44 for securementto a plate l9 and 20 by means of a rivet 45, and an outstanding flange46. r The. brackets 43 each have a plate portion 4'! for securement to aplate Hand 20, and upper andlower flanges 46 to engage adjacent bars 36,the flanges 46 being sely aligned. Accordingly, the bars 36 aresupported by the brackets 42 and 43 in staggered relation in accordancewith the staggered relation of the ends of the banks of tubes 28.

Air guiding means are provided, at the ends of the tubes 28 to smoothout the flow of air as itenters and leaves the'tubes, thereby reducingturbulence and the flow retarding resistance caused by such turbulence.As shown in Figs. 2 and 3 the air guiding means for the ends of thetubes 28 comprises vertically spaced ribs '49 secured to the outer facesof the side walls l9. The ribs 49 are disposed in horizontal planesspaced between the'horizontal planes defined by the banks 26, 21, etc.,of the tubes 28 so that these ribs 49 will occupy positions between theends of the tubes of adjacent banks of, tubes. As shown in Fig, 2,the,ribs 4 9 may be formed by bending a plate 50 along horizontal linesso that there .will be a plurality of vertical plate portions 5| in acommon plane, with outstanding plate portions 52 along the edgesthereof, the outer edges ofadjacent plate portions 52 being connected byrounded or cylindric wall portions 53 so that ridges are provided havingrounded front edges with diverging surfaces formed by the wall portions52." The vertical sections 5| haveopenings 54 therein positioned tocorrespond with the openings 29 of the side plates I9,

so that the extremities 55 of the tubes 28 may project through theopenings 54 and be flanged thereover, thereby holding the formed platemember 50 against the outer face of a side plate I9 of the inter-coolerID. The ferrules 30 are positioned within the ends of the tubes 28 sothat the flanges or lips 3| of these ferrules will lie over the flanges55 of the tube ends, to reinforce the same and' supplement the functionof securing the plates 50 in operative position.

In the preferred use of the invention, the air to be cooled is passedthrough the tubes 28, such air being fed to the tubes through thefittings l5, and, after it leaves the rear end of the tube, beingcarried to the carburetors of 'the, engine or engines through thefitting Hi. The coolant air is passed through the inter-cooler III asindicated by arrows Mia and l6a. Although I have shown front and'rearfittings II and I2,,these fittings need not always be employed, as, forexample, when the inter-cooler I0 is placed in, such position that itwill be exposed to a flow of air. However, in general practice thefittings ll form parts of ducts to connect the inter-cooler l0 with airports in the aircraft structure.

The bars 36 are secured between the vertical I claim as my invention: 1.In an inter-cooler of the character described, the combination of: apair of opposed walls and interconnecting walls forming a fluidpassage,'said pair of opposed walls having openings spaced in planesextending lengthwise ofsaid passage; ,means for directing a flow offluid through said passage lengthwise thereof; banks turbulence in thefluid of tubes placed so as to pass across said passage,

said tubes having the ends thereof secured in said between said finsaligned with said openings to guide fluid into said openings andminimize the as it enters said openlngs. Y i

A 2. In an inter-cooler of the character described, the combination of:apair of opposed,

walls and interconnecting walls forming a fluid passage, said pair ofopposed walls having openings spaced in planes extending lengthwise ofsaid passage; means for directing a flow of fluid through said passagelengthwise thereof; banks of tubesplaced so as .to pass across saidpassage, said tubes having the ends thereof secured in said openings ofsaid opposed walls; and air guide means for said openings at the ends ofsaid tubes, comprising a plate placed adjacent the outer face of one ofsaid opposed walls, having openings to receive the ends of saidttubesand ribs extendingoutward in planes lying between the planes of saidbanks of tubes, said ribs having relatively narrow outer edges andsidewalls which diverge from said edges toward said openings and theextremities of said tubes having flanges outside the outer face of saidplate;

3. In an intercooler ofthe character described,

a the combination of :a pair of npposed walls and interconnecting wallsforming a fluid passage, said pair, of opposed walls having-openingsspaced in planes extending lengthwise of said passage;

banks-of tubes placed so as to pass across said member secured to theouter face of one of said opposed walls and formed so as to provideoutstanding ribs" disposed in planes lying between.

said planes of said banks of tubes, said ribs having relatively narrowouter edges and side walls which diverge from said edges toward saidopen ings, there being openings in said plate between said ribs tocoincide with the ends of said tubes and flanged ferrules extending.into the ends of said tubes to secure said plate against said opposedwall.

4. In an inter-cooler of the character described, the combination of: apair of opposed walls and interconnecting walls forming a fluidof tubeshavinground ends placed so as to pass,

across saidpassage, saidtubes having the ends i thereof secured in saidopenings of said opposed walls; and air guide means for the ends of saidopeningsat-theends of said tubes, comprising a plate member secured tothe outer face of one of said opposed walls and formed so as to provideoutstanding ribs disposed in planes lying between said planes of saidbanks of tubes, said ribs having relatively narrow outer edges and sidewalls which diverge from said edges toward said openings, there beingopenings in said plate between said ribs to coincide with the ends of I

